Fluid pressure brake for motor vehicles



Jan. 19, 1932. E. FRANKLAND 1,842,259I

FLUID PRESSURE BRAKE FOR MOTOR VEHICLES Original Filed Dec. 19, 1923 PetenteaJea. 19', 1932 y Murri-:nv STATES,

PATENT ori-lcs EDWIN FRANKLANDLOF DETROIT, MIGEIGAN, ASSIGNOR TO IBENDIX BRAKE COI- IANY, F SOUTH BEND, INDIANA, A. CORPORATION OF ILLINOIS rLUm PRESSURE :Bam non moron vnmcmzs A'ppneeuen mea December 19,1923, serial Ne. 681,502. Renewed setember 4, i929.

This invention `relates to vehicle brakes and particularl relates to motor vehicle brakes operable by fluid pressure.

The more essential objects of the invention nf are to largely increase the eifective frictional contact area, as compared to present practice, and to consequently permit of a decreased pressure per unit of such area;'

to eiect an intermittent-relief of thevbrakl0 ing pressure, thus preventing locking of the` .wheels, and-reducing heating effect; to insure a perfect equalization of the several brakes. of a vehicle under all load conditions; to minimize the necessary physical l5. effort in effecting an application vof brakes;

and to rovide asbrake construction applicable, without material change of design, to both front and rear wheels'.

In attainin these objects, the invention contemplates ocating within the brake drum of a vehicle wheel an annular expansible fluid receiver arranged between annular sliding". brake ,shoes engageable through expansion of said receiver with disk portions 2vof said drum, said shoes bein suitably restrained from rotation, and ing formed with cam (or equivalent) projections, which, as the wheel rotates, "are engageable, during an application of the brake, with one or more rollers (or equivalent members). upon the drum, so as to intermittently shift the shoes` toa predetermined extent toward each other, thus relieving the braking stress. t y

A preferred uembodiment of the invention is illustrated in the accompanying drawings, wherein,

Fig. 1 is an axial'vertical sectional viewof a wheel equipped' with the improved brake mechanism. y i

Fig. 2 is a plan Viewr of portion of the brake drumbroken away substantially on line2-2-of Fig. 1 to show the cam,` and roller-'means for intermittently reev lievingthe'braking stress. l

Fig. 3l is a view/ of the side of the brake drum adjacent the axle, said view being partly in section on line 3-,3 of Fig. 1.

f In these views' h e reference'character 1 designates'a vehicle wheel, 2 the hub there.

o of, 3 a spindle journaling vsaid hub, 4 a

the same with one of which is secured byA bolts 12 to the flange 7. Within said drum, two annular disk-sha d brake shoes 1-3 are arranged, and are provided with suitable linings 14, also annular, to enga e the `disk portions of the drum when sai shoes are spread apart. T o effect such a spreading, a hollow expansible annulariluid receiving tube 15 is arranged between the shoes 13, and is provided with a nipple 16 projecting toward the axis of the Wheel and connected with a iexible pipe 17 through which a suitable iuid, either ai;l or liquid, may bei troduced into said rece ver, under` pressure, or ma dischargetherefrom. The two brake shoes` 3 are restrained from rotation, 'while permitted to slide to and from eachother, by a collar 18 rigidly mounted upon the knuckle bearing 4, and surroundl in the inner portion of the hub 2, said collar being formed with circumferentially spaced sets of teeth 19, extending parallel to its axis and engaging corresponding teeth 2 0 formed integral upon the inner perlphery of Webs 21 extended radially of the shoes 13. At suitable circumferential intervals, bolts '22 are passed freely through the webs 21,` and 'springs 23 coiled upon the end portions of said bolts urge said ,webs and the shoes 13 toward each other, holdin them normally out'of contact with the dis portions of the drum 8- 9. The shoes 13 are formed with inner annular channels 24 opposed to each..

1 the shoes 13, and at suitable intervals cam enlargements 26 are formed upon the outer faces of said'ilanges. Said enlargements co- ,pther at the outer margins of said shoes, said' act with one or more pairs of rollers 27 -journaled upon bolts 28 projecting radially lease of the brakes, the springs 23 shift the brake shoes clear of the disk faces of the drum, and the cam projections 26 do not then engage the rollers 27.

. From the foregoing description, the operation of the invention is believed apparent. I/Vhen a braking fluid pressure is established within the expansible member l5, the lateral expansion of said member acts equally throughout the entire circumferential extent of said member upon the shoes 13 to urge the same apart and into engagement with the disk surfaces of the drum. Preferably annular pressure plates 29 are arranged between the tube 15 and the brake shoes, said plates being free to slide laterally between inner and outer retainer rings 30, between which the tube 15 is embraced. Said rings prevent any wasted expansion of said tube -in la radial direction. The control means for the flow of fluid through the pipe 17 to andfrom the receiver 15 is no feature of the present invention and is not disclosed. Flexibility of said pipe permits the wheel l to `be swiveled for steering purposes about the king-pin 6, without any effect upon the braking control. For the rear wheels of a vehicle, there may be used substantially the same brake mechanism as is herein described but flexibility of the pipe 17 is not a requisite. It is to be noted that the described fluid pressureactuating means is adapted to equalize` the braking pressureyacting through the two shoes 13, and also to' effect an equal distrib jtion of the pressure throughout the entire farea of the frictionally engaged faces. It is to be further noted that the construction, because of its bafanc'ed applicationl of pressure in opposite directions avoids anyV undesirable axial thrust upon the wheel, either inwardly or outwardly.

What I claim is: v

1. In a vehicle brake, a vehicle wheel, a pair, of co-acting disk brake members, one of which is rotatable with said wheel yand the other relatively stationary, one of said members being slidable axially of thewheel to engage and disengage the other, and automatic means effecting an intermittent release of said `brake members when engaged. Y

2. In a vehicle brake, a vehicle wheel, a disk brake member secured to said wheel to rotate wheel into and out of engagement with said disk member, means restraining vsaid brake shoe from rotationl with the wheel, means for yieldably pressing said brake shoe against said disk member, and elements upon said disk member and shoe engageable through rotation of the wheel in the disk-engaging position of the shoe, to intermittently relieve pressure of said shoe on the disk.

3. In a vehicle brake, a brake drum having spaced disk walls, a pair of annular brake shoes within said drum for engagement with said walls, means between said shoes for shifting the same against said wallsflanges projecting outwardly from said shoes having cam projections upon their remote lateral faces. and rollers mounted upon a peripheral vwall of said drum, engageable by said cam sure arranged within said annular chamber,Y

means. restraining said brakeshoes from rotation, means for delivering a Huid under pressure to said receiver, and means engaging the inner portions of said shoes normally holding the same disengaged from said disks.

5. Brake mechanism comprising a rotatable brake disk member, a non-rotatable brake disk member, said members being normally disengaged, means operable to move one of said members into braking engagement with the other, cam surfaces arranged on opposite sides of the disk members and oppositely disposed with respect to each other and means co-operating therewith during the rotation of the rotatable disk member to intermittently interrupt the braking engagement of said members.

6. Brake mechanism comprising a .rotatable brake disk member, a non-rotatable brake disk member, means yoperable to move one of said members axially into braking engagement with the other, and means operable automatically during the rotation of the rotatable disk member to intermittently interrupt v the braking engagement of said members.

7. Brake mechanismcomprising a rotatable brake disk, a non-rotatable brake disk,

' said discs being normally disengaged, means ldisk and means co-operating therewith to automatically effect an intermittent release of said braking engagement. .y therewith, a brake shoe slidable axially of the 8. Brake mechanism comprising a pair of spaced apart rotatable brake disks, a pair of spaced apart non-rotatable brake disks adaptnadamas ed to be moved-into braking engagement with the rotatable disks, applying means to move said disks into braking enga ement, cam surfaces arranged on opposite aces of the non-f rotatable disks and means (3o-operating therewith to automaticaly intermittently eii'ect a release of such braking engagement.

9. Brake mechanismy comprising a pair of spaced apart rotatable brake disks, a pair of -spaced apart non-rotatable brake disks adapted to be moved .into braking engagement with the rotatable disks, applying means to move said disks into braking engagement, releasing neans independent of the applying means adapted to automatically intermittently effeet a release of such braking engagement.

10. Brake mechanism comprlsing a pair of I spaced apart rotatable brake disks, a pair of .spaced apartnon-rotatable brakedisks adapted to be moved into braking engagement with the rotatablei disks, applying means to move said disks into brakin engagement, releasing means independent o .the action of the applying means adapted to automatically intermittently effect a release of such braking en- -gagement during the application of the applying means.

11. Brake mechanism comprising a rotatable brake disk member, a non-rotatable brake disk member, said, members being normally disengaged, an expansible member to move one of said members into braking engagement with the other, and means operable-automatically during the rotation of the rotatable disk` member to intermittently `depress the expansible member to'interrupt the braking `engagement of said members at aA rate varying directly with the rate 'of rotation of the rotatable disk.

12. Brake mechanism comprising a rotatable brake disk member, a non-rotatable brake disk member, said members being normallydisengaged, means operable tov move one of said members into braki g engagement with the ther, a cam on one ace of the non-rotatabl Iisk, and a member carried by the rop tatablce ldisk adapted to engage said cam to gaged, an expansible means to move one oi`` said members into braking engagement wlth the others, and means operable `to intermittently effect the expansible means.

,15. Brake mechanism for a rotatable wheel ltor a air ot spacedapart brake disks, a non- /ro'tata le torque-taking member arranged axially thereof, a pair of brake'disks non-rotatably supported upon said torque-taking member to be spread apart into braking engagement with the rotatable disks, an expansible luid pressure cell disposed betweensaid nonrotatable disks spaced radially from and independent of the torque-taking member and adapted to be expanded to eect braking engagement of said disks, and means for intermittently depressing said cell. f

16. Brake mechanism for a rotatable wheel having a pair of brake disks spaced axially apart providing an annular chamber therebetween, a pair of brake disks arranged nonrotatably within said chamber adapted 'to'be spread apart axiall into braking engagement'with the 'rotata le disks, said non-rotat-` able disks having normally abutting peripheral flange portlons and normally abutitng axial liange portions and opposed channel port1ons arranged radially between said two flangeportions, and a Huid pressure cell disposed within said channel portions expansileto urge said -disks apart into braking en-" gagement with the rotatable disks.

17. Brake mechanism for a rotatable whee` having a pair of brake disks spaced axially apart providing an annular chamber therebetween, a Vpair of brake .disks arranged nonrotatably within said chamber adapted to be' spread apart axiallyinto braking engagement with the rotatable disks, said non-rotatable disks having normally abutting peripheral flange portions and normally abutting axial liange portions and opposed channel ortions arranged radially between said two ange ortions, means extending through the axial ange portions adapted to exert a ten--y sion thereon tending to hold said disks toward each other, and a fluid pressure cell disosed within said channel portions expansi-l le to urge said disks apart counter the tension o said means into braking engagement with the rotatable \disks.

18. Brake mechanism for a rotatable wheel having a pair of brake disks spaced axially apart providing an'annula'r chamber therebetween, a pair of brake disks arranged nonrotatably within saidchamber adapted to be spread apartI axiall .into braking engagement with the rotata le disks, said non-rotatable ,disks having normally abutting peripheral liange portions and normally abutting axial flange portions and opposed channel portions arranged radially between said two iiange ortions, means extending through the axial ange portions adapted to exert a tension thereon tending to hold said disks toward each other, a Huid pressure cell disposed within said channel portions expansiblefto urge saiddisks apart counter the tension of some means into braking engagement with the rotatablddisk's and means carried by the rotatable brake disks adapted during the rotation of the brake disks to engage at intervals the peripheral iange portions of the nonrotatable disks to urge said disks away from therotatable disksvand out of frictional engagement therewith.

In testimony whereof I sign this specification.

EDWIN FRANKLAND. 

